BACKGROUND
Technical Field
[0001] This disclosure relates generally to electronic devices, and more particularly, to
electronic devices with a flexible display.
Description of the Related Art
[0002] Electronic devices often include displays. For example, cellular telephones and portable
computers include displays for presenting information to a user. Many electronic devices
are now being built on flexible substrates rather than rigid circuit boards or glass.
This allows electronic devices to be flexed or bent to some degree. Like conventional
non-flexible devices, flexible electronic devices include conductive traces, typically
made of metal, that are used to propagate signals within the electronic devices. However,
the conventional designs of conductive traces are prone to cracking and/or delamination
over repeated bending of the electronic devices, resulting in reduced performance
and/or reliability.
[0003] US 2014/0138637 A1 is entitled "
Flexible Display" and discloses an array of thin film transistors (TFTs) on a flexible substrate.
The display includes metal lines respectively coupled to gate, source and drain electrodes
of the TFTs. At least one of the metal lines comprises a non-stretchable portion in
the TFT areas and a stretchable portion outside the TFT areas.
[0004] US 2014/0022746 A1 is entitled "
Strain relief structures for stretchable interconnects" and discloses an intersection structure having elastic properties that relieve a
mechanical strain on bypass regions during stretching.
[0005] WO 2010/086034 A1 is entitled "
Stretchable electronic device" and provides a transition structure between a first (stretchable) electronic structure
and a second (rigid or flexible) electronic structure. The transition structure has
a Young modulus in a range between the Young modulus of the first electronic structure
and the Young modulus of the second electronic structure.
[0006] According to
WO 2010/086416 A1, a "
Stretchable electronic device" comprises a stretchable interconnection electrically connecting two electronic components,
the stretchable interconnection comprising an electrically conductive channel having
a predetermined first geometry by which said channel is stretchable up to a given
elastic limit and a first flexible supporting layer provided for supporting the electrically
conductive channel and having a predetermined second geometry by which said first
supporting layer is stretchable. The predetermined second geometry has a predetermined
deviation from the predetermined first geometry chosen for restricting stretchability
of the electrically conductive channel below its elastic limit.
[0007] GB 2 489 508 A discloses "
Flexible circuit board interconnects" comprising elongate sections joined together by spring sections. The elongate sections
extend at an inclined angle with respect to the longitudinal direction of the interconnection.
The spring sections allow electrical connections to be maintained when the flexible
circuit is subjected to stretching or bending. Multiple parallel interconnection patterns
are also described.
SUMMARY
[0008] The embodiments herein describe a winding conductive trace design that is resistant
to cracking during bending and stretching stresses. The winding conductive trace design
may be incorporated in any flexible electronic device such as a flexible display device,
or in any electronic device that may not necessarily be flexible. In some embodiments,
a winding conductive trace includes a cap located in a low stress region of the winding
conductive trace. The width of a metal trace line located in the regions of the winding
conductive trace that include caps is wider than the width of the metal trace line
located in other regions of the winding conductive trace that lack the caps. The cap
helps ensure electrical connection of the metal trace line even though one or more
cracks may begin to form in the metal trace line.
[0009] In one embodiment, a winding conductive trace splits into multiple sub-traces which
converge back into a single winding conductive trace at certain intervals to prevent
or minimize severance of interconnections by cracks in the winding conductive trace.
An apparatus including multiple sub-traces comprises a flexible substrate and a winding
conductive trace formed over the flexible substrate. The winding conductive trace
includes a first sub-trace and a second sub-trace that is symmetric to the first sub-trace.
The first sub-trace and the second sub-trace are disposed in a mirrored shape and
each includes a plurality of alternating crests and troughs that each has a convex
edge (an outer edge) and a concave edge (an inner edge) positioned opposite the convex
edge. The first sub-trace and the second sub-trace split from the winding conductive
trace and merge back together at a plurality of joints where each joint is located
at a trough of the first sub-trace and a crest of the second sub-trace. A first portion
of the first sub-trace located between each alternating crest and trough of the first
sub-trace is smaller in width than a second portion of the first sub-trace located
between the convex edge and the concave edge of each of the crests and troughs of
the first sub-trace. A first portion of the second sub-trace located between each
alternating crest and trough of the second sub-trace is smaller in width than a second
portion of the second sub-trace located between the convex edge and the concave edge
of each of the crests and troughs of the second sub-trace.
[0010] The invention is defined in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011]
FIGS. 1A, 1B, 2A, and 2B are schematic views of an exemplary flexible display device.
FIGs. 3A and 3B are respectively a schematic plan view and corresponding perspective
view of a winding conductive trace of the exemplary flexible display device.
FIG. 4 is a detailed view of the winding conductive trace according to Figures 3A,
3B.
FIG. 5 is a cross-section view of the wire trace according to Figure 4.
FIG. 6 is a detailed view of another exemplary winding conductive trace.
FIG. 7 is a detailed view of still another exemplary winding conductive trace.
FIG. 8A is a detailed view of mirrored conductive traces according to one embodiment.
FIG. 8B illustrates a staggered arrangement of multiple mirrored conductive traces
according to one embodiment.
FIG. 9 is a view of mirrored conductive traces according to another embodiment.
DETAILED DESCRIPTION
FLEXIBLE DISPLAY DEVICE
[0012] FIG. 1 illustrates an exemplary flexible display 100 which may be incorporated in electronic
devices. The flexible display 100 includes at least one active area (i.e., display
area), in which an array of display pixels are formed. Each pixel may be associated
with a corresponding pixel circuit, which may be coupled to one or more signal lines
for communicating with the driving circuits (e.g., a gate driver, a data driver, etc.)
to activate the pixels. By way of an example, each pixel circuit may be electrically
connected to a gate line and a data line.
[0013] The flexible display 100 may include one or more inactive areas at the periphery
of the active area. That is, the inactive area may be adjacent to one or more sides
of the active area such that the active area may be partly or entirely surrounded
by the inactive area. For instance, the active area of the flexible display 100 may
have a square or a rectangular shape, and the inactive area of the flexible display
100 may surround the active area. However, it should be appreciated that the shapes
of the active area and the inactive area are not particularly limited. The active
area and the inactive area may be in any shape according to the design of the electronic
device employing the flexible display 100. Non-limiting examples of the active area
shapes in the flexible display 100 include a pentagonal shape, a hexagonal shape,
a circular shape, an oval shape, and more.
[0014] The flexible display 100 can include various circuits, which may be used in generating
various signals, for example, signals operating the pixels of the flexible display
100 and signals for sensing touch inputs from a user, and various other functionality
associated with the flexible display 100 and/or the electronic device employing the
flexible display 100.
[0015] Some of the circuits may be mounted on an external printed circuit and coupled to
a connection interface (Pads/Bumps) disposed in the inactive area using flexible printed
circuit board (FPCB), chip-on-film (COF), tape-carrier-package (TCP) or any other
suitable technologies. Also, some of the circuits may be implemented with one or more
transistors fabricated in the inactive area of the flexible display 100. For example,
one or more gate drivers may be implemented with transistors fabricated in the inactive
area as depicted in
FIG. 1A. Such gate drivers may be referred to as a gate-in-panel (GIP). It should be appreciated
that other types of driving circuits, including but not limited to, an inverter circuit,
a multiplexer, data driver, source driver, electro static discharge (ESD) circuit
and the like, may also be formed in the inactive area of the flexible display 100.
[0016] The transistors used in implementing such driving circuits in the inactive area are
not particularly limited. That is, the type of transistors used in implementing the
driving circuits in the inactive area need not be the same as the transistors used
for implementing the pixel circuits in the active area. The type of transistors may
be selected according to the operating conditions and/or requirements of the transistors
in the corresponding circuit.
[0017] In the embodiments herein, parts of the flexible display 100 may be defined by a
central portion and a bend portion. One or more bend portions of the flexible display
100 can be bent away from the tangent plane at a certain bend angle and a bend radius
around the bending axis. A bend portion of the flexible display 100 can be bent away
in an inclination angle or in a declination angle at a bend line BL.
[0018] The bend line BL may extend horizontally (e.g., X-axis shown in FIG. 1A), vertically
(e.g., Y-axis shown in FIG. 1A) or even diagonally in the flexible display 100, or
in any other direction of the flexible display 100. Multiple portions of the flexible
display 100 can be bent. Accordingly, one or more edges of the flexible display 100
can be bent away from the plane of the central portion along the several bend lines
BL. While the bend line BL is depicted as being located towards the edges of the flexible
display 100 in the example of FIG. 1A, it should be appreciated that the location
the bend lines BL is not limited as such. Any one or more corners of the flexible
display 100 may be bent as well. The flexible display 100 can be bent in any combination
of horizontal, vertical and/or diagonal directions based on the desired design of
the flexible display 100. The bend line BL may be run across the central portion of
the flexible display 100 to provide a foldable display or a double-sided display having
display pixels on both outer sides of a folded display.
[0019] For example, the central portion of the flexible display 100 may be substantially
flat, and one or more bend portions may be bent away from the tangent plane of the
central portion. The size of each bend portion that is bent away from the central
portion need not be the same.
[0020] In some embodiments, the radius of curvatures (i.e., bend radius) for the bend portions
in the flexible display 100 may be between about 0.1 mm to about 10 mm, between about
0.1 mm to about 5 mm, or between about 0.1 mm to about 1 mm, or between about 0.1
mm to about 0.5 mm. The smallest bend radius of the bend portion of the flexible display
100 may be less than 0.5 mm.
[0021] While the central portion of the flexible display 100 may have a flat surface, some
embodiments may not have such a flat central portion. The central portion of the flexible
display 100 can be curved-in or curved-out as depicted in
FIG. 1B, providing flexible display 100 with a concave or a convex central portion. Even in
the embodiments with a convex or concave curved central portion, one or more bend
portions of the flexible display 100 can be bent inwardly or outwardly along the bend
line at a bend angle around a bend axis.
[0022] In FIG. 1A, the bend portion of the flexible display 100 may include an active area
capable of displaying an image from the bend portion, which is referred hereinafter
as the secondary active area. That is, the bend line can be positioned in the active
area so that at least some display pixels of the active area are included in the bend
portion that is bent away from the plane of the central portion of the flexible display
100. In this case, the matrix of display pixels in the secondary active area of the
bend portion may be continuously extended from the matrix of the display pixels in
the active area of the central portion as depicted in
FIG. 2A. Alternatively, the secondary active area within the bend portion and the active area
within the central portion of the flexible display 100 may be separated apart from
each other by the outer bend radius as depicted in
FIG. 2B.
[0023] The secondary active area in the bend portion may serve as a secondary display area
in the flexible display 100. The size of the secondary active area is not particularly
limited. The size of the secondary active area may depend on its functionality within
the electronic device. For instance, the secondary active area may be used to provide
images and/or texts such a graphical user interface, buttons, text messages, and the
like. In some cases, the secondary active area may be used to provide light of various
colors for various purposes (e.g., status indication light), and thus, the size of
the secondary active area need not be as large as the active area in the central portion
of the flexible display 100.
[0024] The pixels in the secondary active area and the pixels in the central active area
may be addressed by the driving circuits (e.g., gate driver, data driver, etc.) as
if they are in a single matrix. In this case, the pixels of the central active area
and the pixels of the secondary active area may be operated by the same set of signal
lines (e.g., gate lines, emission lines, etc.). By way of example, the N
th row pixels of the central active area and the N
th row pixels of the secondary active area may be configured to receive a signal from
the driving circuit via the conductive traces crossing over the bend allowance section
as depicted in FIG. 2B.
[0025] In some embodiments, the pixels in the secondary active area may be driven discretely
from the pixels in the central active area. That is, the pixels of the secondary active
area may be recognized by the display driving circuits as being an independent matrix
of pixels separate from the matrix of pixels in the central active area. In such cases,
the pixels of the central active area and the pixels of the secondary active area
may utilize different sets of signal lines from each other. Further, the secondary
active area may employ one or more display driving circuits discrete from the ones
employed by the central active area.
[0026] There are several conductive traces included in the flexible display 100 for electrical
interconnections between various components therein. The circuits, for instance the
ones fabricated in the active area and inactive area, may transmit various signals
via the conductive traces to provide a number of functionalities in the flexible display
100. As briefly discussed, some conductive traces may be used to provide electrical
interconnections between the circuits and/or other components in the central portion
and the bend portion of the flexible display 100.
[0027] In the embodiments herein, the conductive traces may include source/drain electrodes
of the TFTs as well as the gate lines/data lines used in transmitting signals from
some of the display driving circuits (e.g., gate driver-IC, data driver-IC) in the
inactive area to the pixels in the active area. Likewise, some conductive traces like
touch sensor electrodes or fingerprint sensor electrodes may provide signals for sensing
touch input or recognizing fingerprints on the flexible display 100. The conductive
traces can also provide interconnections between the pixels of the active area in
the central portion and the pixels of the secondary active area in the bend portion
of the flexible display 100. Still other conductive traces may be used to provide
power (e.g., supply voltage) to circuit components within the flexible display 100.
Aforementioned uses of conductive traces are merely illustrative. As used herein,
the conductive traces broadly refer to a conductive path for transmitting any type
of electrical signals, power and/or voltages from one point to another point in the
flexible display 100.
[0028] Some of the conductive traces may be extended from the central portion to the bend
portion of the flexible display 100. In such cases, some portions of the conductive
traces may be configured differently from the other portions to withstand the bending
stress. In particular, the portion of the conductive traces over at least the bend
allowance section of the flexible display 100 may include several features that can
reduce cracks and fractures of the conductive traces to maintain proper interconnection.
[0029] At least some of the conductive traces may have a multi-layered structure, which
may allow more stretching (or flexibility) with less chance of breakage and to reduce
galvanic corrosion as will be further described below.
CONDUCTIVE TRACES
[0030] A conductive trace may be multi-layered. The conductive trace may include a lower
protection layer such as a passivation layer, a metal layer which is a metal trace
line formed on the lower protection layer, and an upper protection layer such as a
passivation layer that is formed on the metal layer, as will be further described
below in more detail with respect to
FIG. 5.
[0031] The trace design is determined by considering the electrical requirements of the
conductive trace as well as the type of signals transmitted on the conductive trace.
Also, the properties of the materials (e.g., Young's modulus) used in forming the
conductive trace can be considered in designing the traces. It should be noted that
various other factors such as a thickness, a width, a length, a layout angle for a
section as well as for the entirety of the metal trace line and the passivation layers
may need to be considered to provide a trace design having sufficient electrical and
mechanical reliability for use in the flexible display 100.
[0032] The conductive trace design may be specifically tailored for the conductive trace
based on their placement and orientation in reference to the bending direction (i.e.,
tangent vector of the curve) of the flexible display 100. A conductive trace will
be subjected to more bending stress as the orientation in which the conductive trace
extends is more aligned to the tangent vector of the curvature. In other words, a
conductive trace will withstand better against the bending stress when the length
of the conductive trace aligned to the tangent vector of the curvature is reduced.
[0033] In order to reduce the length of the conductive trace portion being aligned to the
tangent vector of the curvature, conductive traces of the flexible display 100 may
employ any one or more winding designs as will be further described below. In such
configurations, the bending stress may be distributed to the trace portions oriented
in an angle shifted away from the tangent vector of the curvature.
[0034] FIGs. 3A and 3B respectively illustrate a plan view and a perspective view of a winding conductive
trace 300. As shown in FIGs. 3A and 3B, the winding conductive trace 300 is formed
on a flexible substrate 302 and a cover layer 301 is formed on the substrate 302 to
cover and protect the winding conductive trace 300 from external elements such as
moisture or air that can degrade the winding conductive trace 300.
[0035] The winding conductive traces 300A, 300B, and 300C may have a winding trace pattern
that is curved and includes caps as will be further described with respect to
FIG. 4. The winding trace pattern of the winding conductive trace 300 is more resistant to
bending and stretching stresses compared to conventional trace patterns (e.g., straight
line trace patterns or sine wave wire patterns) due to the caps included in the winding
conductive traces 300. In the example shown in FIGs. 3A and 3B, the winding conductive
traces 300 are subject to bending in either direction perpendicular to the substrate
302 (e.g., the "z" axis direction as shown in FIG. 3B) or in an angled direction,
as shown with the arrows. The winding conductive trace 300 maintains integrity without
cracking or delamination when the flexible display 100 is bent as will be further
described below.
[0036] FIG. 4 is a detailed plan view of a winding conductive trace 300. The winding conductive
trace 300 resembles a temple gate structure. The width of the metal trace line 401
is represented by the dashed lines in FIG. 4 and varies depending on the location
on the winding conductive trace 300. The passivation layer 403 generally has a width
that is larger than that of the metal trace line 401 throughout the winding conductive
trace 300, and the width of the passivation layer 403 in various portions of the winding
conductive trace 300 corresponds to the width of the metal trace line 401. In other
words, in a plan view as depicted in FIG. 4, the trace shape of the passivation layer
403 is substantially identical to the trace shape of the metal trace line 401, but
with a predetermined margin beyond the width of the metal trace line 401.
[0037] The metal trace line 401 may be formed of conductive materials such as copper, gold,
silver, and other types of coated or printed materials. Although the term "metal trace
line" is used, it should be noted that the metal trace line in the winding conductive
trace 300 may be replaced with other types of conductive materials, such as carbon
based materials (e.g., graphene, carbon nanotube), conducting polymers, and other
non-metal based conductive materials. Furthermore, the metal trace line need not be
straight. The metal trace line can be curved. With bend radius requirement at the
bend allowance section of the flexible display 100, however, the materials for forming
the winding conductive trace 300 should meet the minimum mechanical requirement and
the size requirement as well as the stringent electrical requirements of the flexible
display 100. The metal trace line 401 can comprise one or more metal layers such as
aluminum and other metals. In circumstances requiring less flexibility in the winding
conductive trace 300, molybdenum or other conductive materials discussed above may
be used.
[0038] The passivation layer 403 may be formed of inorganic materials which are generally
less ductile than the metal trace line 401 of the winding conductive trace 300. Examples
of the materials used to form the passivation layer include inorganic materials such
as silicon nitride, silicon dioxide and other dielectric materials commonly used in
semiconductor device and other electronics processing.
[0039] Given the same amount of bending stress, cracks generally initiate from the passivation
layer of the winding conductive trace 300. Even if the metal trace lines have sufficient
strength to withstand the bending stress without cracking, cracks are generally initiated
from the passivation layer and tend to grow and propagate into the metal trace lines
of the winding conductive trace 300, creating spots of poor electrical contacts that
could render the flexible display 100 unusable. Accordingly, various bending stress
reduction techniques may be utilized in both the passivation layers and the metal
trace line of the winding conductive traces 300.
[0040] As shown in FIG. 4, the winding conductive trace 300 includes a plurality of alternating
crests 405 (e.g., 405A, 405B, ...) and alternating troughs 407 (e.g., 407A, 407B,
...). Each crest 405 includes a convex edge 408 (e.g., 408A) of the winding conductive
trace 300 exhibiting the local maximum amounts of upward distance in the y-direction
from the rest of the portions of the winding conductive trace 300. In Figure 4, the
convex edge 408 is a surface (e.g., a first edge) of the winding conductive trace
300 that is curved like the exterior of a trapezoid. Conversely, each trough 407 includes
another convex edge 408 (e.g., 408B) of the winding conductive trace 300 exhibiting
the local maximum of downward distance in the y-direction from the rest of the portions
of the winding conductive trace 300.
[0041] The total distance from a convex edge of a crest (e.g., e.g., 408A) to a convex edge
of a trough (e.g., 408B) of the winding conductive trace 300 in the y-direction represents
the height of winding conductive trace 300. The total distance from a first crest
405A to an adjacent second crest 405B in the x-direction represents the pitch (width)
of the winding conductive trace 300. The pitch of the winding conductive trace 300
may be approximately one time (1X) the height of the winding conductive trace 300.
However, other pitches may be used such as 0.3 times (0.3X) to 0.5 times (0.5X) the
height of the winding conductive trace 300 or 2 times (2X) to 3 times (3X) the height
of the winding conductive trace 300.
[0042] Additionally, each crest 405 and trough 407 of the winding conductive trace 300 includes
a concave edge 412, (412A, 412B, ...) located opposite to the convex edge 408 of each
respective crest and trough. A concave edge 412 of each crest and trough is substantially
rounded (e.g., like a half-circle) in shape with a radius that is maximized according
to the height and pitch of the winding conductive trace 300. The concave edge 412
represents a surface (e.g., a second edge) of the winding conductive trace 300 that
curves inward like the interior of a circle or sphere. It should be noted that the
concave edges 412 may have shapes other than a half circle. The trace of the concave
edges 412 may simply be more rounded than the trace of the convex edges at the troughs
and crests.
[0043] During bending of the flexible display 100 (e.g., in the "z" axis direction), the
concave edge 412 of the winding conductive trace 300 is an area of high stress whereas
the convex edges 408 are areas of low stress. Cracks typically start to occur at the
passivation layer 403 located at the concave edges 412 of the winding conductive trace
300 during bending of the flexible display 100. The cracks tend to grow and propagate
into the metal trace line 401 of the winding conductive trace 300 thereby creating
spots of poor electrical contacts that could render the flexible display 100 unusable.
[0044] The winding conductive trace 300 may include caps 409 (409A, 409B, 409C...) that
are portions of the metal trace line 401 located between the convex edges 4085 and
concave edges 412 of each crest 405 and trough 407 and extend beyond the width 413
of the metal trace line without the cap 409. The width 411 of the metal trace line
401 located in the regions of the winding conductive trace 300 that include the caps
409 is wider than the width 413 of the metal trace line 401 located in intermediate
portions 421 of the winding conductive trace 300 located between each alternating
crest (e.g., 405A) and trough (e.g., 407A or 407B). Due to the wider width 411 of
the metal trace line 401 including the cap regions 409 (e.g., 409A, 409B, 409C...),
cracks in the passivation layers located at the concave edges 412 will not propagate
across the entire width 411 of the metal trace line 401, and thus electrical connections
will be maintained even if cracks are formed in the concave edges 412 due to bending.
For example, the metal trace line 401 in crest 405A is provided with a cap 409A. If
a crack propagates across a portion of the width 411 of the metal trace line 401,
spots of poor electrical contact are prevented since the width 411 of the metal trace
line 401 including cap 409A is wider than the width 413 of the metal trace line 401
at the intermediate portions 421. Furthermore, since the cap 409A is located at a
low stress region of the winding conductive trace 300 during bending of the flexible
display 100, it is unlikely for the crack to propagate across the width 411 of the
metal trace line 401 including cap 409A. The cap 409 may be similar to a trapezoid
in shape as shown in FIG. 4. The trapezoidal shape of the cap 409 is defined by the
convex edge 408 of the winding conductive trace 300.
[0045] The width 411 of the metal trace line 401 may be roughly three times the width 413
of the concentric circle segment (e.g., concave edge 412). Although the cap 409 is
described as being trapezoidal in shape 300, the cap 409 can be other shapes which
can be chosen based on electric static discharge (ESD) requirements, stress requirements,
and nesting requirements as will be further described below.
[0046] The intermediate portion 421 may include the passivation layers 403 and the metal
trace line 401 that extend from the portion of the winding conductive trace 300 located
between a convex 408 edge and a concave edge 412 located opposite the convex edge
408. As shown in FIG. 4, the intermediate portion 421 lacks (i.e., does not have)
the cap 409. In other words, the width of the winding conductive trace 300 is at its
minimum at the intermediate portion 421.
[0047] The width 411 of the metal trace line 401 located between the convex edge 408 and
concave edge 412 of a crest/trough that includes a cap 409 is larger than the width
413 of the metal trace line 401 located at the intermediate portion 421 that lacks
the cap 409. In contrast, the width of the passivation layers 403 varies based on
the position of the winding conductive trace 300. That is, the width of the passivation
layers 403 varies according to the width of the metal trace line 401. For example,
the width of the passivation layer 403 located in the intermediate portion 421 may
be smaller than the width of the passivation layer located between a convex edge 408
and a concave edge 412 opposite the convex edge of each crest and/or trough.
[0048] FIG. 5 is a cross-section view of the winding conductive trace 300 along line A to A'
shown in FIG. 4. As shown in FIG. 5, the winding conductive trace 300 includes a first
passivation layer 501 formed on the substrate 302. The first passivation layer 501
may be made of inorganic material such as silicon oxide (SiO2), silicon nitride (SiNx),
and a combination of both. The substrate 302 may be made of flexible material such
as polyimide.
[0049] The metal trace line 401 is formed on the first passivation layer 501. The metal
trace line 401 may be made of aluminum or may be a combination of conductive material.
A second passivation layer 505 is formed over the metal trace line 401. The second
passivation layer 505 can also be made of inorganic material such as SiO2 and/or SiNx.
As shown in FIG. 5, the first passivation layer 501 and the second passivation layer
505 cover all sides of the metal trace line 401. The first passivation layer 501 and
the second passivation layer 505 form a protective layer around the metal trace line
401 that protects the metal trace line 401 from moisture and/or air. The first passivation
layer 501, the second passivation layer 505, and the metal trace line 401 collectively
represent the winding conductive trace 300. As shown in FIG. 5, a cover layer 301
is formed over the second passivation layer 505, the metal trace line 401, the first
passivation layer 501, and the substrate 302 to provide further protection from moisture
and/or air. The cover layer 301 can be made of any polymer. The total height 509 of
the winding conductive trace 300 may be 10 to 1000 nm.
[0050] The width of the first passivation layer 501 and the width of the second passivation
layer 505 may be designed to extend past edges 513 of the metal trace line 401. The
first passivation layer 501 and second passivation layer 505 are designed to be long
enough to protect the metal trace 401 from moisture and/or air, but cannot be too
long as the first passivation layer 501 and second passivation layer 505 may crack
too easily when bent. The portion 511A of the first passivation layer 501 and the
second passivation layer 501 may extend past edge 513A of the metal trace line 401
and portion 511B of the first passivation layer 501 and the second passivation layer
501 may extend past edge 513B of the metal trace line 401. The portions 511 that extend
past the edges 513 of the metal trace line 401 may be at most 10 µm.
[0051] As mentioned previously, the width of the passivation layers vary based on the position
of the winding conductive trace 300. For example, the width of the first passivation
layer 501 in the intermediate portion 421 has a width that is smaller than the width
of the first passivation layer 501 in the portion of the winding conductive trace
300 between a convex edge 408 and concave edge 412 of each crest and trough. Similarly,
the width of the second passivation layer 505 in the intermediate portion 421 has
a width that is smaller than the width of the second passivation layer 505 in the
portion of the trace 300 between a convex edge and concave edge. The width of the
first passivation layer 501 and the width of the second passivation layer 505 in the
intermediate portion 421 may be substantially the same, and the width of the first
passivation layer 501 and the width of the second passivation layer 505 in the portion
of the winding conductive trace 300 between a convex edge and a concave edge of a
crest and trough may be substantially the same.
[0052] The target bending radii of curvature of the flexible display device 100 may be as
small as 0.1 mm if a cover layer 301 is applied as shown in FIG. 5. The cover layer
301 is chosen to place the winding conductive trace 300 in or near the mechanical
neutral plane of the flexible display device 100. The design of the cover layer 301
is based on the thickness, modulus, and residual stress of the substrate 302 and cover
layer 301. Since the winding conductive trace 300 including the passivation layers
501, 505 and metal trace 401 is typically very thin compared to the substrate 302
and cover layer 301, the thickness of the passivation layers 501, 503 and metal trace
401 can be ignored when designing the thickness of the cover layer 301. The neutral
plane design of the cover layer 301 may be calculated according to the following equation:
[0053] As shown above, the product of the modulus of the substrate 302 and the thickness
of the substrate 302 squared is equivalent to the product of the modulus of the cover
layer 301 and the thickness of the cover layer 301 squared in order to keep the substrate
302 and the cover layer 301 bending together without being delaminated when bent.
Once the materials for the substrate 302 and cover layer 301 are known as well as
the thickness of the substrate 302, the thickness of the cover layer 301 can be determined.
[0054] FIG. 6 illustrates another exemplary trace pattern of a winding conductive trace 600. As
mentioned above, FIGs. 3-4 illustrate a winding conductive trace with a trapezoidal
shaped cap 409. In contrast, FIG. 6 illustrates a winding conductive trace 600 with
rounded caps 601. The rounded shape of the cap is defined by the convex edge 603 of
the winding conductive trace 600. The winding conductive trace 600 includes similar
features as the winding conductive trace 300 described above, the description of which
is omitted for brevity.
[0055] The rounded cap 601 reduces the generation of electrical fields between adjacent
winding conductive traces that use the rounded cap 601. In contrast, winding conductive
traces that use pointed caps such as trapezoidal caps 409 may increase the electrical
field formed between two adjacent winding conductive traces. Strong electrical fields
generated between adjacent traces may cause the passivation layers covering the metal
trace to deteriorate. On the other hand, winding conductive traces 600 using rounded
caps 601 may not be able to be packed as tightly together due to the larger surface
area of the rounded cap 601, compared to the trapezoidal shaped cap 409.
[0056] FIG. 7 illustrates another exemplary winding conductive trace 700. In particular, FIG. 7
illustrates a winding conductive trace 700 with triangular caps 701. The triangular
shape of the cap 701 is defined by the convex edge 703 of the winding conductive trace
700. The winding conductive trace 700 also includes similar features as the winding
conductive trace 300 described above, the description of which is omitted for brevity.
[0057] The triangular cap 701 improves the ability to tightly pack more winding conductive
traces 700 together due to the smaller surface area of the triangular shaped cap 701
compared to the rounded cap 601. However, the triangular cap 701 may increase the
electrical field formed between adjacent winding conductive traces due to the pointed
nature of the triangular cap 701. The sharp points of the triangular cap 701 may increase
the electrical field generated between adjacent winding conductive traces, which in
turn may cause the passivation layers covering the metal wire trace to deteriorate.
MIRRORED WIRING
[0058] In order to prevent or minimize severance of interconnections by cracks in the winding
conductive traces, the winding conductive traces may split into multiple sub-traces,
which converge back into a single trace at certain intervals.
FIG. 8A illustrates a detailed view of a mirrored trace 800 according to one embodiment.
The mirrored trace 800 includes two symmetric winding conductive traces that are adjoined
in a mirrored configuration and are symmetric with respect to the line of symmetry
shown in FIG. 8A. The mirrored trace 800 resembles a double temple gate structure.
In the example shown in FIG. 8A, the mirrored trace 800 is composed of two winding
conductive traces each of which with a trapezoidal cap as shown in FIG. 4. The mirrored
trace 800 is alternatively composed of two winding conductive traces each of which
with a rounded cap as shown in FIG. 6 or two winding conductive traces each of which
with a triangular cap as shown in FIG. 7.
[0059] In one embodiment, the mirrored trace 800 includes sub-trace A and sub-trace B, which
merge back together at every joint 813. The metal trace line of sub-trace A and sub-trace
B at joint 813 may have a height in the y-direction of 17.48 µm. Each sub-trace A,
B is multi-layered such that the trace of the passivation layer covers at least some
part of the metal trace lines. The width of the mirrored trace 800 corresponds to
the width 801 of the passivation layer, and the width 803 is the width of the metal
trace line that is at least partially covered by the passivation layer similar to
the single winding conductive trace described above. In one embodiment, the width
803 of the metal trace line may be in a range of about 2 µm to about 3 µm. In one
embodiment, the distance 814 that the passivation layer extends past the edge of the
metal trace line may be in a range of about 1.0 µm to about 1.5 µm.
[0060] As shown in FIG. 8A, sub-trace A has a winding conductive trace pattern that includes
a plurality of alternating crests (e.g., crest 805A) and troughs (e.g., trough 807A).
Each crest 805 and trough 807 includes a convex edge 806 (e.g., 806A and 806B) and
a concave edge 812 (e.g., 812A and 812B) similar to the description described above
with respect to FIG. 4. Similarly, sub-trace B also has a winding conductive trace
pattern that includes a plurality of alternating crests (e.g., crests 805B) and troughs
(e.g., trough 807B). Each crest and trough of sub-trace B also includes a convex edge
806 and a concave edge 812 similar to the description described above with respect
to FIG. 4. The total distance from the convex edge of crest 805A of sub-trace A to
the convex edge of trough 807B of sub-trace B in the y-direction represents the height
of the mirrored trace 800.
[0061] Sub-trace A includes a cap 809A and sub-trace B includes a cap 809B at low stress
portions of the mirrored trace 800 to prevent cracks from propagating across the width
816 of the metal trace line that include the cap, in order to prevent poor electrical
contact. The cap top 818 represents a substantially flat edge of the caps 809.
[0062] As mentioned above, the crest 805 of sub-trace A also has a concave edge 812A and
the trough 809B of sub-trace B has a concave edge 812B that are substantially rounded,
like a half-circle in shape. During bending of the flexible display 100, the concave
edges 812 of the crests and troughs are areas of high stress whereas the convex portions
(e.g., 806) of the crests and troughs are areas of low stress. Cracks typically start
to occur at the passivation layer located at the concave edges 812 of the crests and
troughs of the mirrored trace 800 during bending of the flexible display 100. The
rounded shape of the concave edges 812 of sub-trace A and sub-trace B distribute the
mechanical stress over the larger area of the concave edges 812 thereby reducing the
onset of a crack generation.
[0063] However, if cracks occur at the passivation layer located at the concave edges 812
of the mirrored trace 800, they could grow and propagate into the metal trace lines
of the mirrored traces 800. Advantageously, if a crack propagates across a portion
of the width 816 of the metal trace line, spots of poor electrical contact are prevented
since the width 816 of the metal trace line include the cap region 809 that is wider
than the width 803 of the metal trace line at the intermediate portions without the
cap 809. Furthermore, since the cap 809 is located at a low stress region, it is unlikely
that cracks will propagate across the width 816 of the metal trace line that includes
the cap 809 during bending of the flexible display 100. In one embodiment, alternating
concave edges of a sub-trace have different radii. For example, concave edge 812A
of sub-trace A may have a radius of 8.1 µm whereas concave edge 812C of sub-trace
A may have a radius of 9.46 µm. In other embodiments, alternating concave edges of
the sub-trace may have substantially the same radii.
[0064] Furthermore, by splitting the mirrored trace 800 into multiple sub-traces, a backup
electrical pathway is provided in case one of the sub-traces is damaged by cracks.
As such, the mirrored trace 800 can be used in the bend portion, and may be particularly
helpful within the bend allowance section subjected to severe bending stress.
[0065] Referring now to
FIG. 8B, a plurality of mirrored traces 800 are shown in a staggered configuration. In FIG.
8B, the mirrored traces 800 are positioned adjacent to each other in a staggered configuration
to maximize the number of wires in a given area. The mirrored traces 800 are staggered
such that the convex edge of a given double-temple gate trace is placed in line with
a concave edge of an adjacent mirrored trace. The size of the mirrored trace can be
reduced or increased for more efficient use of the given space. Furthermore, the dimension
of two adjacent mirrored traces can be different from each other. For example, the
size of the concave edge of a first mirrored trace can be larger or smaller than the
size of the concave edge of an adjacent second mirrored trace.
[0066] For example, FIG. 8B includes a first mirrored trace 815. A second mirrored trace
817 is adjacent to a first sub-trace of the first mirrored trace 815 and a third mirrored
trace 819 is adjacent to a second sub-trace of the first mirrored trace 815. In one
embodiment, each convex edge 821 of the first sub-trace of the first mirrored trace
815 is positioned in line with a corresponding concave edge 823 of the second mirrored
trace 817. Similarly, each concave edge 825 of the second sub-trace of the first mirrored
trace 815 is positioned in line with a corresponding convex edge 827 of the third
mirrored trace 817. By staggering the mirrored traces, more mirrored traces can be
fit in a given area.
[0067] In one embodiment, the mirrored traces split into additional number of sub-traces,
creating a grid-like trace 900 in the bending area of the flexible display 100 as
illustrated in
FIG. 9. As an example, the sub-traces can be configured to form a web of mirrored traces
800 that resemble a grid 900. Such a trace design may be useful for traces that transmit
a common signal, for example supply voltage signals, VSS and VDD, for the display
100. If one of the traces cracks due to bending, redundancy of the mirrored traces
still allows for the transmission of the common signal. Neither the number of sub-traces
nor the shape of the sub-traces forming the grid-like trace design are particularly
limited to the example shown in FIG. 9. In some embodiments, the sub-traces may converge
into a single trace past the bend allowance section of the flexible display 100.
[0068] As shown in FIG. 9, the grid-like trace 900 includes a first mirrored trace 901,
a second mirrored trace 903, and a third mirrored trace 905, and so on. In one embodiment,
each convex edge of a mirrored trace is connected to a corresponding convex edge of
an adjacent mirrored trace. For example, in FIG. 9 each convex edge 907 of the right
sub-trace of the first mirrored trace 901 is connected to a corresponding convex edge
909 of the left sub-trace of the second mirrored trace 903. Similarly, each convex
edge 911 of the right sub-trace of the second mirrored trace 903 is connected to a
corresponding convex edge 913 of a left sub-trace of the third mirrored trace 905.
[0069] The strain reducing trace designs discussed above may be used for all or parts of
the conductive trace. In some embodiments, the part of conductive trace in the bend
portion of the flexible display 100 may adopt such a strain reducing trace design.
The parts of a conductive trace prior to or beyond the part with the strain reducing
trace design may have the same trace design or a different trace design. If desired,
the strain reducing trace designs may be applied to multiple parts of a conductive
trace.
[0070] Even with the strain reducing trace design, the inevitable bending stress remains
at certain points of the trace (i.e., stress point). The location of stress point
is largely dependent on the shape of the trace as well as the bending direction. It
follows that, for a given bending direction, the trace of a wire and/or an insulation
layer can be designed such that the remaining bending stress would concentrate at
the desired parts of their trace. Accordingly, a crack resistance area can be provided
in a trace design to reinforce the part of the wire trace where the bend stress concentrates.
[0071] While the embodiments herein are described with respect to a flexible display, other
flexible electronic devices can use the various trace designs described above. For
example, the embodiments herein may be incorporated in wearable electronic devices
that are designed to be flexed and worn on surfaces of the human body such as flexible
electronic watches. Other examples in which the embodiments herein may be incorporated
are mobile phones that are bendable, rolled displays for use in electronic tangible
media such as electronic newspapers, magazines, and books. The embodiments herein
may also be incorporated in flexible display screens of televisions. The foregoing
is merely illustrative of the principles of this invention and various modifications
can be made by those skilled in the art without departing from the scope of the appended
claims.
1. An apparatus (100) comprising:
a flexible substrate (302); and
a first winding conductive trace (815) formed over the flexible substrate, the first
winding conductive trace including a first sub-trace (A) and a second sub-trace (B)
that is symmetric to the first sub-trace, the first sub-trace (A) and the second sub-trace
(B) disposed in a mirrored shape and each including a plurality of alternating crests
(805A; 805B) and troughs (807A; 807B) that each have a convex edge (806A; 806B) and
a concave edge (812A, 812C; 812B) which is positioned opposite the convex edge at
the corresponding crest or trough, the first sub-trace (A) and the second sub-trace
(B) splitting from the first winding conductive trace and merging back together at
a plurality of joints (813), each joint located at a trough (807A) of the first sub-trace
(A) and a crest (805B) of the second sub-trace (B);
wherein a first portion (803) of the first sub-trace (A) located between each alternating
crest (805A) and trough (807A) of the first sub-trace (A) is smaller in width than
a second portion (809A) of the first sub-trace (A) located between the convex edge
(806A) and the concave edge (812A) of each of the crests (805A) and troughs (807A)
of the first sub-trace (A), and
wherein a first portion of the second sub-trace (B) located between each alternating
crest (805B) and trough (807B) of the second sub-trace (B) is smaller in width than
a second portion (809B) of the second sub-trace (B) located between the convex edge
(806B) and the concave edge (812B) of each of the crests (805B) and troughs (807B)
of the second sub-trace (B).
2. The apparatus of claim 1, wherein the apparatus further includes:
a second winding conductive trace (817) formed over the flexible substrate (302) and
adjacent to the first winding conductive trace (815), the second winding conductive
trace including a third sub-trace and a fourth sub-trace that is symmetric to the
third sub-trace, the third sub-trace and the fourth sub-trace disposed in a mirrored
shape and each including a plurality of alternating crests and troughs that each have
a convex edge and a concave edge which is positioned opposite the convex edge at the
corresponding crest or trough, the third sub-trace and the fourth sub-trace splitting
from the second winding conductive trace and merging back together at a plurality
of joints, each joint located at a trough of the third sub-trace and a crest of the
fourth sub-trace;
wherein a first portion of said third sub-trace located between each alternating crest
and trough of the third sub-trace is smaller in width than a second portion of said
third sub-trace located between the convex edge and the concave edge of each of the
crests and troughs of the third sub-trace,
wherein a first portion of the fourth sub-trace located between each alternating crest
and trough of the fourth sub-trace is smaller in width than a second portion of the
fourth sub-trace located between the convex edge and the concave edge of each of the
crests and troughs of the fourth sub-trace, and
wherein the first winding conductive trace (815) is staggered with respect to the
second winding conductive trace (817) such that a convex edge (821; 827) of either
the first sub-trace (A) or the second sub-trace (B) of the first winding conductive
trace (815) is disposed in line with a concave edge (823; 825) of either the third
sub-trace or the fourth sub-trace of the second winding conductive trace (817).
3. The apparatus of claim 1, wherein the apparatus further includes: a second winding
conductive trace (903) formed over the flexible substrate (302) and adjacent to the
first winding conductive trace (901), the second winding conductive trace including
a third sub-trace and a fourth sub-trace that is symmetric to the third sub-trace,
the third sub-trace and the fourth sub-trace disposed in a mirrored shape and each
including a plurality of alternating crests and troughs that each have a convex edge
and a concave edge which is positioned opposite the convex edge at the corresponding
crest or trough, the third sub-trace and the fourth sub-trace splitting from the second
winding conductive trace and merging back together at a plurality of joints, each
joint located at a trough of the third sub-trace and a crest of the fourth sub-trace;
wherein a first portion of said third sub-trace located between each alternating crest
and trough of said third sub-trace is smaller in width than a second portion of said
third sub-trace located between the convex edge and the concave edge of each of the
crests and troughs of the third sub-trace, wherein a first portion of said fourth
sub-trace located between each alternating crest and trough of said fourth sub-trace
is smaller in width than a second portion of said fourth sub-trace located between
the convex edge and the concave edge of each of the crests and troughs of the fourth
sub-trace, wherein each convex edge (907) of the first winding conductive trace 2.
(901) is connected to a corresponding convex edge (909) of the second winding conductive
trace (903) forming a grid (900) of winding conductive traces (901, 903, 905).
4. The apparatus of claim 1, wherein the second portion of the first sub-trace (A) and
the second portion of the second sub-trace (B) each include a cap (809A; 809B) comprising
a metal trace, 2. the width of the second portion including the width of the metal
trace called width of the metal trace.
5. The apparatus of claim 4, wherein the second portion of the first sub-trace (A) and
the second portion of the second sub-trace (B) between the convex edge and the concave
edge of each of the crests and troughs each further include:
a first passivation layer having a first width (801); and
a second passivation layer having a second width that is substantially the same as
the first width;
wherein the cap (809A; 809B) is formed between the first passivation layer and the
second passivation layer and is enclosed by the first passivation layer and the second
passivation layer.
6. The apparatus of claim 5, wherein the first width (801) of the first passivation layer
and the second width of the second passivation layer in the second portion of the
first sub-trace (A) and in the second portion of the second sub-trace (B) located
between the convex edge and the concave edge is larger than the third width (816)
of the metal trace included in the cap (809A; 809B) located between the convex edge
and the concave edge.
7. The apparatus of claim 5, wherein the first portion of the first winding conductive
sub-trace (815) further includes the first passivation layer, the second passivation
layer, and the metal trace with a fourth width that is smaller than the third width,
and wherein the first passivation layer, the second passivation layer, and the metal
trace extend from the second portion of the first sub-trace (A) and from the second
portion of the second sub-trace (B) to the respective first portions, and
wherein the first passivation layer included in the first portion has a fifth width
that is smaller than the first width of the first passivation layer in the second
portion of the winding conductive trace between the convex edge and the concave edge,
and the second passivation layer included in the first portion has a sixth width that
is smaller than the second width of the second passivation layer in the second portion
of the winding conductive trace between the convex edge and the concave edge, the
sixth width substantially the same as the fifth width.
8. The apparatus of claim 7, wherein the width of the first portion of the first sub-trace
is smaller than the width of the respective second portion of each of the first sub-trace
(A) and the second sub-trace (B) located between the convex edge and the concave edge.
9. The apparatus of claim 4, wherein
- the cap (809A; 809B) is trapezoidal in shape and the shape is defined by the convex
edge of the crest or trough in which the cap is located, or
- the cap is triangular in shape and the shape is defined by the convex edge of the
crest or trough in which the cap is located, or
- the cap is rounded in shape and the shape is defined by the convex edge of the crest
or trough in which the cap is located.
10. The apparatus of claim 1, wherein the concave edge is curved.
11. The apparatus of claim 1, wherein the distance from the convex edge (806A) of one
of the crests of the first sub-trace (A) to 2. the convex edge (807B) of the corresponding
trough of the second sub-trace (B) is the height of the first winding conductive trace
(815), and the distance from said one of the crests of the first sub-trace to an adjacent
one of the crests of the first sub-trace (A; B) is substantially the same as the height
of the first winding conductive trace (815).
12. The apparatus of claim 1, wherein the distance from the convex edge (806A) of one
of the crests of the first sub-trace (A) to 2. the convex edge (807B) of the corresponding
trough of the second sub-trace (B) is the height of the first winding conductive trace
(815), and the distance from said one of the crests of the first sub-trace to an adjacent
one of the crests of the first sub-trace (A; B) is selected from a range of a third
of the height of the first winding conductive trace (815) to three times the height
of the first winding conductive trace (815).
13. The apparatus of claim 1, wherein the apparatus is
- a flexible television, or
- an electronic device wearable on a surface of a human body, or
- a mobile phone, or
- an electronic newspaper.
1. Eine Vorrichtung (100), aufweisend:
ein flexibles Substrat (302); und
eine erste gewundene Leiterbahn (815), die über dem flexiblen Substrat gebildet ist,
wobei die erste gewundene Leiterbahn eine erste Sub-Leiterbahn (A) und eine zweite
Sub-Leiterbahn (B), die zu der ersten Sub-Leiterbahn symmetrisch ist, aufweist, wobei
die erste Sub-Leiterbahn (A) und die zweite Sub-Leiterbahn (B) in einer spiegelbildlichen
Form angeordnet sind und jeweils eine Mehrzahl von alternierenden Bergen (805A; 805B)
und Tälern (807A; 807B), die jeweils eine konvexe Kante (806A; 806B) und eine konkave
Kante (812A, 812C; 812B), die an dem entsprechenden Berg oder Tal gegenüberliegend
zu der konvexen Kante positioniert ist, aufweisen, wobei sich die erste Sub-Leiterbahn
(A) und die zweite Sub-Leiterbahn (B) von der ersten gewundenen Leiterbahn abspalten
und an einer Mehrzahl von Verbindungsstellen (813) wieder zusammengeführt sind, wobei
jede Verbindungsstelle an einem Tal (807A) der ersten Sub-Leiterbahn (A) und einem
Berg (805B) der zweiten Sub-Leiterbahn (B) angeordnet ist;
wobei ein erster Abschnitt (803) der ersten Sub-Leiterbahn (A), der zwischen jedem
alternierenden Berg (805A) und Tal (807A) der ersten Sub-Leiterbahn (A) angeordnet
ist, in einer Breite kleiner ist als ein zweiter Abschnitt (809A) der ersten Sub-Leiterbahn
(A), der zwischen der konvexen Kante (806A) und der konkaven Kante (812A) von jedem
der Berge (805A) und Täler (807A) der ersten Sub-Leiterbahn (A) angeordnet ist, und
wobei ein erster Abschnitt der zweiten Sub-Leiterbahn (B), der zwischen jedem alternierenden
Berg (805B) und Tal (807B) der zweiten Sub-Leiterbahn (B) angeordnet ist, in einer
Breite kleiner ist als ein zweiter Abschnitt (809B) der zweiten Sub-Leiterbahn (B),
der zwischen der konvexen Kante (806B) und der konkaven Kante (812B) von jedem der
Berge (805B) und Täler (807B) der zweiten Sub-Leiterbahn (B) angeordnet ist.
2. Die Vorrichtung gemäß Anspruch 1, wobei die Vorrichtung ferner aufweist:
eine zweite gewundene Leiterbahn (817), die über dem flexiblen Substrat (302) und
benachbart zu der ersten gewundenen Leiterbahn (815) gebildet ist, wobei die zweite
gewundene Leiterbahn eine dritte Sub-Leiterbahn und eine vierte Sub-Leiterbahn, die
symmetrisch zu der dritten Sub-Leiterbahn ist, aufweist, wobei die dritte Sub-Leiterbahn
und die vierte Sub-Leiterbahn in einer spiegelbildlichen Form angeordnet sind und
jeweils eine Mehrzahl von alternierenden Bergen und Tälern, die jeweils eine konvexe
Kante und eine konkave Kante, die an dem entsprechenden Berg oder Tal gegenüberliegend
zu der konvexen Kante positioniert ist, aufweisen,
wobei sich die dritte Sub-Leiterbahn und die vierte Sub-Leiterbahn von der zweiten
gewundenen Leiterbahn abspalten und an einer Mehrzahl von Verbindungsstellen wieder
zusammengeführt sind, wobei jede Verbindungsstelle an einem Tal der dritten Sub-Leiterbahn
und einem Berg der vierten Sub-Leiterbahn angeordnet ist;
wobei ein erster Abschnitt der dritten Sub-Leiterbahn, der zwischen jedem alternierenden
Berg und Tal der dritten Sub-Leiterbahn angeordnet ist, in einer Breite kleiner ist
als ein zweiter Abschnitt der dritten Sub-Leiterbahn, der zwischen der konvexen Kante
und der konkaven Kante von jedem der Berge und Täler der dritten Sub-Leiterbahn angeordnet
ist,
wobei ein erster Abschnitt der vierten Sub-Leiterbahn, der zwischen jedem alternierenden
Berg und Tal der vierten Sub-Leiterbahn angeordnet ist, in einer Breite kleiner ist
als ein zweiter Abschnitt der vierten Sub-Leiterbahn, der zwischen der konvexen Kante
und der konkaven Kante von jedem der Berge und Täler der vierten Sub-Leiterbahn angeordnet
ist, und
wobei die erste gewundene Leiterbahn (815) in Bezug auf die zweite gewundene Leiterbahn
(817) derart gestaffelt ist, dass eine konvexe Kante (821; 827) von entweder der ersten
Sub-Leiterbahn (A) oder der zweiten Sub-Leiterbahn (B) der ersten gewundenen Leiterbahn
(815) in einer Linie mit einer konkaven Kante (823; 825) von entweder der dritten
Sub-Leiterbahn oder der vierten Sub-Leiterbahn der zweiten gewundenen Leiterbahn (817)
angeordnet ist.
3. Die Vorrichtung gemäß Anspruch 1, wobei die Vorrichtung ferner aufweist: eine zweite
gewundene Leiterbahn (903), die über dem flexiblen Substrat (302) und benachbart zu
der ersten gewundenen Leiterbahn (901) gebildet ist, wobei die zweite gewundene Leiterbahn
eine dritte Sub-Leiterbahn und eine vierte Sub-Leiterbahn, die symmetrisch zu der
dritten Sub-Leiterbahn ist, aufweist, wobei die dritte Sub-Leiterbahn und die vierte
Sub-Leiterbahn in einer spiegelbildlichen Form angeordnet sind und jeweils eine Mehrzahl
von alternierenden Bergen und Tälern, die jeweils eine konvexe Kante und eine konkave
Kante, die an dem entsprechenden Berg oder Tal gegenüberliegend zu der konvexen Kante
positioniert ist, aufweisen, wobei die dritte Sub-Leiterbahn und die vierte Sub-Leiterbahn
sich von der zweiten gewundenen Leiterbahn abspalten und an einer Mehrzahl von Verbindungsstellen
wieder zusammengeführt sind, wobei jede Verbindungsstelle an einem Tal der dritten
Sub-Leiterbahn und einem Berg der vierten Sub-Leiterbahn angeordnet ist; wobei ein
erster Abschnitt der dritten Sub-Leiterbahn, der zwischen jedem alternierenden Berg
und Tal der dritten Sub-Leiterbahn angeordnet ist, in einer Breite kleiner ist als
ein zweiter Abschnitt der dritten Sub-Leiterbahn, der zwischen der konvexen Kante
und der konkaven Kante von jedem der Berge und Täler der dritten Sub-Leiterbahn angeordnet
ist, wobei ein erster Abschnitt der vierten Sub-Leiterbahn, der zwischen jedem alternierenden
Berg und Tal der vierten Sub-Leiterbahn angeordnet ist, in einer Breite kleiner ist
als ein zweiter Abschnitt der vierten Sub-Leiterbahn, der zwischen der konvexen Kante
und der konkaven Kante von jedem der Berge und Täler der vierten Sub-Leiterbahn angeordnet
ist, wobei jede konvexe Kante (907) der ersten gewundenen Leiterbahn (901) mit einer
entsprechenden konvexen Kante (909) der zweiten gewundenen Leiterbahn (903) verbunden
ist, wobei ein Gitter (900) aus gewundenen Leiterbahnen (901, 903, 905) gebildet ist.
4. Die Vorrichtung gemäß Anspruch 1, wobei der zweite Abschnitt der ersten Sub-Leiterbahn
(A) und der zweite Abschnitt der zweiten Sub-Leiterbahn (B) jeweils eine Kappe (809A;
809B) aufweisen, die eine Metallbahn aufweist, wobei die Breite des zweiten Abschnitts
die Breite der Metallbahn, die als eine dritte Breite der Metallbahn bezeichnet ist,
enthält.
5. Die Vorrichtung gemäß Anspruch 4, wobei der zweite Abschnitt der ersten Sub-Leiterbahn
(A) und der zweite Abschnitt der zweiten Sub-Leiterbahn (B) zwischen der konvexen
Kante und der konkaven Kante von jedem der Berge und Täler jeweils ferner aufweist:
eine erste Passivierungsschicht, die eine erste Breite (801) aufweist; und
eine zweite Passivierungsschicht, die eine zweite Breite aufweist, die im Wesentlichen
gleich der ersten Breite ist;
wobei die Kappe (809A; 809B) zwischen der ersten Passivierungsschicht und der zweiten
Passivierungsschicht gebildet ist und mittels der ersten Passivierungsschicht und
der zweiten Passivierungsschicht eingeschlossen ist.
6. Die Vorrichtung gemäß Anspruch 5, wobei die erste Breite (801) der ersten Passivierungsschicht
und die zweite Breite der zweiten Passivierungsschicht in dem zweiten Abschnitt der
ersten Sub-Leiterbahn (A) und in dem zweiten Abschnitt der zweiten Sub-Leiterbahn
(B), der zwischen der konvexen Kante und der konkaven Kante angeordnet ist, größer
ist als die dritte Breite (816) der Metallbahn, die in der Kappe (809A; 809B), die
zwischen der konvexen Kante und der konkaven Kante angeordnet ist, enthalten ist.
7. Die Vorrichtung gemäß Anspruch 5, wobei der erste Abschnitt der ersten gewundenen
leitfähigen Sub-Leiterbahn (815) ferner die erste Passivierungsschicht, die zweite
Passivierungsschicht und die Metallbahn mit einer vierten Breite, die kleiner ist
als die dritte Breite, aufweist, und wobei die erste Passivierungsschicht, die zweite
Passivierungsschicht und die Metallbahn sich von dem zweiten Abschnitt der ersten
Sub-Leiterbahn (A) und von dem zweiten Abschnitt der zweiten Sub-Leiterbahn (B) zu
den entsprechenden ersten Abschnitten erstreckt, und
wobei die erste Passivierungsschicht, die in dem ersten Abschnitt enthalten ist, eine
fünfte Breite aufweist, die kleiner ist als die erste Breite der ersten Passivierungsschicht
in dem zweiten Abschnitt der gewundenen Leiterbahn zwischen der konvexen Kante und
der konkaven Kante, und die zweite Passivierungsschicht, die in dem ersten Abschnitt
enthalten ist, eine sechste Breite aufweist, die kleiner ist als die zweite Breite
der zweiten Passivierungsschicht in dem zweiten Abschnitt der gewundenen Leiterbahn
zwischen der konvexen Kante und der konkaven Kante, wobei die sechste Breite im Wesentlichen
gleich der fünften Breite ist.
8. Die Vorrichtung gemäß Anspruch 7, wobei die Breite des ersten Abschnitts der ersten
Sub-Leiterbahn kleiner ist als die Breite des entsprechenden zweiten Abschnitts von
jeder der ersten Sub-Leiterbahn (A) und der zweiten Sub-Leiterbahn (B), der zwischen
der konvexen Kante und der konkaven Kante angeordnet ist.
9. Die Vorrichtung gemäß Anspruch 4, wobei
- die Kappe (809A; 809B) in ihrer Form trapezförmig ist und die Form mittels der konvexen
Kante des Bergs oder Tals, in dem die Kappe angeordnet ist, definiert ist, oder
- die Kappe in ihrer Form dreieckig ist und die Form mittels der konvexen Kante des
Bergs oder Tals, in dem die Kappe angeordnet ist, definiert ist, oder
- die Kappe in ihrer Form gerundet ist und die Form mittels der konvexen Kante des
Bergs oder Tals, in dem die Kappe angeordnet ist, definiert ist.
10. Die Vorrichtung gemäß Anspruch 1, wobei die konkave Kante gebogen ist.
11. Die Vorrichtung gemäß Anspruch 1, wobei der Abstand von der konvexen Kante (806A)
von einem der Berge der ersten Sub-Leiterbahn (A) zu der konvexen Kante (807B) des
entsprechenden Tals der zweiten Sub-Leiterbahn (B) die Höhe der ersten gewundenen
Leiterbahn (815) ist, und der Abstand von dem einen der Berge der ersten Sub-Leiterbahn
zu einem benachbarten der Berge der ersten Sub-Leiterbahn (A; B) im Wesentlichen gleich
der Höhe der ersten gewundenen Leiterbahn (815) ist.
12. Die Vorrichtung gemäß Anspruch 1, wobei der Abstand von der konvexen Kante (806A)
von einem der Berge der ersten Sub-Leiterbahn (A) zu der konvexen Kante (807B) des
entsprechenden Tals der zweiten Sub-Leiterbahn (B) die Höhe der ersten gewundenen
Leiterbahn (815) ist, und der Abstand von dem einen der Berge der ersten Sub-Leiterbahn
zu einem benachbarten der Berge der ersten Sub-Leiterbahn (A; B) ausgewählt ist aus
einem Bereich eines Drittels der Höhe der ersten gewundenen Leiterbahn (815) bis zum
Dreifachen der Höhe der ersten gewundenen Leiterbahn (815).
13. Die Vorrichtung gemäß Anspruch 1, wobei die Vorrichtung
- ein flexibles Fernsehen, oder
- eine elektronische Vorrichtung, die auf einer Oberfläche eines menschlichen Körpers
getragen werden kann, oder
- ein Mobiltelefon, oder
- eine elektronische Zeitung ist.
1. Dispositif (100), comprenant :
un substrat flexible (302) ; et
une première trace conductrice enroulée (815) formée sur le substrat flexible, la
première trace conductrice enroulée comprenant une première sous-trace (A) et une
deuxième sous-trace (B) qui est symétrique à la première sous-trace, la première sous-trace
(A) et la deuxième sous-trace (B) étant disposées en miroir et comprenant chacune
une pluralité de crêtes (805A, 805B) et de creux (807A, 807B) alternés qui ont chacun
un bord convexe (806A, 806B) et un bord concave (812A, 812C, 812B) qui est positionné
à l'opposé du bord convexe au niveau de la crête ou du creux correspondants, la première
sous-trace (A) et la deuxième sous-trace (B) se séparant de la première trace conductrice
enroulée et se réunissant à nouveau en une pluralité de joints (813), chaque joint
étant situé au niveau d'un creux (807A) de la première sous-trace (A) et d'une crête
(805B) de la deuxième sous-trace (B) ;
dans lequel une première partie (803) de la première sous-trace (A) située entre chaque
crête (805A) et creux (807A) alternés de la première sous-trace (A) est plus petite
en largeur qu'une deuxième partie (809A) de la première sous-trace (A) située entre
le bord convexe (806A) et le bord concave (812A) de chacun des crêtes (805A) et creux
(807A) de la première sous-trace (A), et
dans lequel une première partie de la deuxième sous-trace (B) située entre chaque
crête (805B) et creux (807B) alternés de la deuxième sous-trace (B) est plus petite
en largeur qu'une deuxième partie (809B) de la deuxième sous-trace (B) située entre
le bord convexe (806B) et le bord concave (812B) de chacun des crêtes (805B) et creux
(807B) de la deuxième sous-trace (B).
2. Dispositif selon la revendication 1, dans lequel le dispositif comprend en outre :
une deuxième trace conductrice enroulée (817) formée sur le substrat flexible (302)
et adjacente à la première trace conductrice enroulée (815), la deuxième trace conductrice
enroulée comprenant une troisième sous-trace et une quatrième sous-trace qui est symétrique
à la troisième sous-trace, la troisième sous-trace et la quatrième sous-trace étant
disposées en miroir et comprenant chacune une pluralité de crêtes et de creux alternés
qui ont chacun un bord convexe et un bord concave qui est positionné à l'opposé du
bord convexe au niveau de la crête ou du creux correspondants, la troisième sous-trace
et la quatrième sous-trace se séparant de la deuxième trace conductrice enroulée et
se réunissant à nouveau en une pluralité de joints, chaque joint étant situé au niveau
d'un creux de la troisième sous-trace et d'une crête de la quatrième sous-trace ;
dans lequel une première partie de ladite troisième sous-trace située entre chaque
crête et creux alternants de la troisième sous-trace est plus petite en largeur qu'une
deuxième partie de ladite troisième sous-trace située entre le bord convexe et le
bord concave de chacun des crêtes et creux de la troisième sous-trace,
dans lequel une première partie de la quatrième sous-trace située entre chaque crête
et creux alternants de la quatrième sous-trace est plus petite en largeur qu'une deuxième
partie de la quatrième sous-trace située entre le bord convexe et le bord concave
de chacun des crêtes et creux de la quatrième sous-trace, et
dans lequel la première trace conductrice enroulée (815) est décalée par rapport à
la deuxième trace conductrice enroulée (817) de telle sorte qu'un bord convexe (821,
827) de la première sous-trace (A) ou de la deuxième sous-trace (B) de la première
trace conductrice enroulée (815) est disposé en ligne avec un bord concave (823, 825)
de la troisième sous-trace ou de la quatrième sous-trace de la deuxième trace conductrice
enroulée (817).
3. Dispositif selon la revendication 1, dans lequel le dispositif comprend en outre :
une deuxième trace conductrice enroulée (903) formée sur le substrat flexible (302)
et adjacente à la première trace conductrice enroulée (901), la deuxième trace conductrice
enroulée comprenant une troisième sous-trace et une quatrième sous-trace qui est symétrique
à la troisième sous-trace, la troisième sous-trace et la quatrième sous-trace étant
disposées en miroir et comprenant chacune une pluralité de crêtes et de creux alternés
qui ont chacun un bord convexe et un bord concave qui est positionné à l'opposé du
bord convexe au niveau de la crête ou du creux correspondants, la troisième sous-trace
et la quatrième sous-trace se séparant de la deuxième trace conductrice enroulée et
se réunissant à nouveau en une pluralité de joints, chaque joint étant situé au niveau
d'un creux de la troisième sous-trace et d'une crête de la quatrième sous-trace ;
dans lequel une première partie de ladite troisième sous-trace située entre chaque
crête et creux alternés de ladite troisième sous-trace est plus petite en largeur
qu'une deuxième partie de ladite troisième sous-trace située entre le bord convexe
et le bord concave de chacun des crêtes et creux de la troisième sous-trace, dans
lequel une première partie de ladite quatrième sous-trace située entre chaque crête
et creux alternés de ladite quatrième sous-trace est plus petite en largeur qu'une
deuxième partie de ladite quatrième sous-trace située entre le bord convexe et le
bord concave de chacun des crêtes et creux de la quatrième sous-trace, dans lequel
chaque bord convexe (907) de la première trace conductrice enroulée (901) est connecté
à un bord convexe correspondant (909) de la deuxième trace conductrice enroulée (903)
formant une grille (900) de traces conductrices enroulées (901, 903, 905).
4. Dispositif selon la revendication 1, dans lequel la deuxième partie de la première
sous-trace (A) et la deuxième partie de la deuxième sous-trace (B) comprennent chacune
un capuchon (809A, 809B) comprenant une trace métallique, la largeur de la deuxième
partie comprenant la largeur de la trace métallique appelée troisième largeur de la
trace métallique.
5. Dispositif selon la revendication 4, dans lequel la deuxième partie de la première
sous-trace (A) et la deuxième partie de la deuxième sous-trace (B) entre le bord convexe
et le bord concave de chacun des crêtes et creux comprennent chacune en outre :
une première couche de passivation ayant une première largeur (801) ; et
une deuxième couche de passivation ayant une deuxième largeur qui est sensiblement
la même que la première largeur ;
dans lequel le capuchon (809A, 809B) est formé entre la première couche de passivation
et la deuxième couche de passivation et est entouré par la première couche de passivation
et la deuxième couche de passivation.
6. Dispositif selon la revendication 5, dans lequel la première largeur (801) de la première
couche de passivation et la deuxième largeur de la deuxième couche de passivation
dans la deuxième partie de la première sous-trace (A) et dans la deuxième partie de
la deuxième sous-trace (B) située entre le bord convexe et le bord concave est supérieure
à la troisième largeur (816) de la trace métallique comprise dans le capuchon (809A,
809B) situé entre le bord convexe et le bord concave.
7. Dispositif selon la revendication 5, dans lequel la première partie de la première
sous-trace conductrice enroulée (815) comprend en outre la première couche de passivation,
la deuxième couche de passivation et la trace métallique avec une quatrième largeur
qui est inférieure à la troisième largeur, et dans lequel la première couche de passivation,
la deuxième couche de passivation et la trace métallique s'étendent de la deuxième
partie de la première sous-trace (A) et de la deuxième partie de la deuxième sous-trace
(B) aux premières parties respectives, et
dans lequel la première couche de passivation comprise dans la première partie a une
cinquième largeur qui est inférieure à la première largeur de la première couche de
passivation dans la deuxième partie de la trace conductrice enroulée entre le bord
convexe et le bord concave, et la deuxième couche de passivation comprise dans la
première partie a une sixième largeur qui est inférieure à la deuxième largeur de
la deuxième couche de passivation dans la deuxième partie de la trace conductrice
enroulée entre le bord convexe et le bord concave, la sixième largeur étant sensiblement
la même que la cinquième largeur.
8. Dispositif selon la revendication 7, dans lequel la largeur de la première partie
de la première sous-trace est inférieure à la largeur de la deuxième partie respective
de chacune de la première sous-trace (A) et de la deuxième sous-trace (B) située entre
le bord convexe et le bord concave.
9. Dispositif selon la revendication 4, dans lequel
- le capuchon (809A, 809B) est de forme trapézoïdale et la forme est définie par le
bord convexe de la crête ou du creux où le capuchon est situé, ou
- le capuchon est de forme triangulaire et la forme est définie par le bord convexe
de la crête ou du creux ou le capuchon est situé, ou
- le capuchon est de forme arrondie et la forme est définie par le bord convexe de
la crête ou du creux où le capuchon est situé.
10. Dispositif selon la revendication 1, dans lequel le bord concave est incurvé.
11. Dispositif selon la revendication 1, dans lequel la distance du bord convexe (806A)
de l'une des crêtes de la première sous-trace (A) au bord convexe (807B) du creux
correspondant de la deuxième sous-trace (B) est la hauteur de la première trace conductrice
enroulée (815), et la distance de ladite une des crêtes de la première sous-trace
à une crête adjacente des crêtes de la première sous-trace (A, B) est sensiblement
la même que la hauteur de la première trace conductrice enroulée (815).
12. Dispositif selon la revendication 1, dans lequel la distance du bord convexe (806A)
de l'une des crêtes de la première sous-trace (A) au bord convexe (807B) du creux
correspondant de la deuxième sous-trace (B) est la hauteur de la première trace conductrice
enroulée (815), et la distance de ladite une des crêtes de la première sous-trace
à une crête adjacente des crêtes de la première sous-trace (A, B) est choisie dans
une plage d'un tiers de la hauteur de la première trace conductrice enroulée (815)
à trois fois la hauteur de la première trace conductrice enroulée (815).
13. Dispositif selon la revendication 1, dans lequel le dispositif est
- une télévision flexible, ou
- un dispositif électronique pouvant être porté sur une surface d'un corps humain,
ou
- un téléphone portable, ou
- un journal électronique.